Answer:
5 feet
Explanation:
When you place the 13 foot ladder, the ladder, floor, and wall forms a right triangle and the ladder will become the hypotenuse.
We use the Pythagorean Theorem. Let x be the distance from the building.
x^2 +12^2 = 13^2
x^2 + 144 = 169
x^2 = 169 - 144
x^2 = 25
Take the square root of 25 and you get 5
x = 5